Underreamer



W. B.' WIGLE. UNDERREAMER. APELlcATloN FILED Aue.12, 191s.

Patented Oct. 26, 1920.

.Il llvkl) TTORNEY "PATENT OFFICE.

WILSON IB. WIGLE, OF FULLERTON, CALIFORNIA.

UNDEnrtE'Ai/TER.

To all rwhom t may concern Be it known that I, WiLsoN B. WIGLE, a citizen of the Dominion of Canada, residing at Fullerton, in the county of Orange and State of California, have invented new and useful Improvements in Underreamers, of which the following is a specification.

My invention relates more particularly to an underreamer construction utilized in enlarging the drilling holes of oil and other wells, and refers more particularly to my improved underreamer construction illustrated and described in my U. S. Letters Patent, 1,273,708, dated July 23, 1918.

main object of my present invention is to avoid all unnecessary strain on the keeper pins that connect the cutters tothe cutter operating rod. G

A further object of my invention is to provide a guiding means for the cutter operating rod, whereby a cylindrical rod may be employed, thus obviating the necessity offorming rectangular drills in the shells and cutters of the underreamer.

Another object of my invention is to provide means for temporarily locking the cutters in collapsed position while they are being inserted into the well tubing, or while they are being removed for sharpening or for other purposes.

Further advantageous details of construction will be amplified in the construction hereinafter described and illustrated in the accompanying drawings, in which:

Figure 1 is a central longitudinal section through my underreamer construction illusf trating the cutters in an expanded position, and in dotted lines in a collapsed position.

Fig. 2 is a side elevation of the lower end of the underreamer, the well hole being in section and the cutters expanded.

Fig. 3 is a view similar to Fig. 2 but with the cutters in a collapsed position.

Fig. 4 is a section taken on line 4-4 of Fig. 1 looking inthe direction indicated by the arrows thereon.

Fig. 5 is a cross sectionv taken on lines 5--5 of Fig. 1 looking in the direction indicated by the arrows thereon.

Fig. 6 is a cross section taken on line 6-6 of Fig. 1 looking in the direction indicated by the arrows thereon, and illustrating the connections of the cutter operating rod with the cutters.

In the drawings, 10 designates thev upper solid portion of the body of my improved underreamer, provided on its lower end Specification of Letters Patent. Paten-fed tin Application led August 12, 1918. Serial No. 249,521.

with a tapered threaded socket 11, which is engaged by the threaded tapered end 12 on the upper end of the tool shell 13, in which is mounted the cutter operating mechanism.

The upper portion of the tool shell 13 is provided with a circular bore 14which eX- tends from its upper end downwardly to approximately one-half of its length, another bore 15 of yless diameter than bore 14 continuing downwardly a short distance, the juncture of the two bores forming an annular shoulder 16. The lowerend of the shell 13 is provided with a tapered recess or socket 17 adapted to receive the tapered cutter Shanks 18 and 19. Recess 17 is connect# ed with bore 14 by a cylindrical bore 2O through which passes the cutter operating rod 21, whose function will be more particularly described hereinafter.

oct. 2e, 1926.

The lower end of the shell 13 on its rightl' angled diameters is provided with tapered recesses or sockets adapted to receive the tapered lugs 23 formed at the base of the cutter Shanks 18 and 19 to prevent a rotation of the cutters when the same are in an operative position, as illustrated in Figs. 1 and 2 of the drawings. The cutters 22 and 24 are identical, each having a tapered shank 18 and 19, as heretofore noted, which conforms to the tapered recess 17 formed on the lower end of the shell portion 13. The outer surface of the' shell 13 is liattened as at 35 in order that a wrench may engage therearound so that the upper portion and lower portion of the underreamer may be disengaged when desired. f

Disposed within the bores formed within the shell 13 is a cutter operating rod 31 which is cylindrical throughout its entire length, the upper end Iof said rod being threaded as at 27 for the reception of a nut 28, which is provided with transversely disposed key slots 29 near its upper end for the reception of a key or guide 30. The ends of key rod 30 project within vertically and diametrically disposed guide slots 31 formed in the surface of bore 14. It will be seen by this construction that the rod 21 is prevented from turning and also that the nut is locked lirmly in its adjusted position on the rod. Surrounding the operating rod 21 is the spring 41, the upper end of which abuts against the nut 28, the lower end abutagainst the shoulder 26.

n the lower end of the cutter operatin rod 21 is secured the cross bar 32 adapte to fit into recesses 33 and 34 formed in the cutters 22 and 24. The outer extending ends of the cross bar 32 are rounded on their upper surfaces which are adapted to engage with the concaved shoulders 35 and 36 formed in the cutters 22 and 24. The outwardly extending ends of the cross bar 32 are provided with circular perforations 37 and 38, through which pass the keeper pins 39 and 40, which are of smaller diameter than the perforations 37 and 38, the outer ends of said pins engaging tightly in perforations formed in the cutters, the eX- treme ends of said pins being slightly headed over to prevent displacement.

It will be noted from the above described construction that when the cutters are in operation, as shown in Figs. 1 and 2 all strain on the keeper pins 39 and 40, due to the heavy pressure exerted by the spring 41, is eliminated, the rounded ends of the cross bar 32 abutting against the concaved shoulders 35 and 36 of the cutters, thus preventing any strain upon thekeeper pins.

To collapse the cutters preparatory to inserting them into the tubing, or for any other purpose, a tool or handle of any desirable shape is screwed into the threaded bore 42 formed in the lower edge of the cross bar 32. The rod 21 is then drawn downwardly against the pressure of' the spring 41 until the top of the nut 28 reaches a point just below the perforations 43 drilled in the sides of the shell 13. A key 44 shown in dotted lines is then inserted in perforations 43, passing over the top of the nut. 28, all of which is clearly shown in dotted lines in Fig. 1 of the drawings. The tool or handle is then disengaged from the cross bar and thel cutters drop into collapsed position.

After the cutters have been inserted into the wvell tubing 45 the key 44 is removed, and the cutters are still held in collapsed position by the engagement of the rounded shoulders 46 formed on the cutters, with the inner wall of the tubing. The shell and cutters are then pushed downwardly in the well tubing until the shoulders 46 pass beyond the lower end thereof. The spring 41 then acts to extend`t`he cutters into operative position, as clearly shown in Fig. 2 of the drawings.

When it is desired to remove the underreamer from the well tubing, the body is lifted, the rounded shoulders 46 of the cutters then engage with the lower edge of the tubing, thereby retarding the upward movement of the cutters until the shanks 18 and 19 have been withdrawn from the recess 17 sufficiently to allow the cutters to collapse and enter the tubing, when they are then drawn up through the tubing and shell, as clearly shown 1n drawings.

What I claim is:

1. In an underreamer, the combination of rig. sof the with the body a shell, a spring pressed rod slidably mounted in said shell, a cross bar rigidly secured on the lower end of said rod and having perforations in its outer ends, cutters movably secured to said cross bar, keeper pins passing through said perforations, said pins being of smaller diameter than the perforations, and shoulders provided on the cutters adapted to engage the ends of the cross bar, whereby all strain upon the keeper pins due to the tension of the spring will be avoided.

2. In an underreamer, the combination of a shell, a rod slidably mounted in said shell, resilient means tending to retract said rod, cutters pivotally mounted on said rod, a guide slot formed in said shell, and a key secured to said rod adapted to engage in said slot, whereby said rod may be prevented from turning in said shell but will be permitted to reciprocate therein.

3. In an underreamer, the combination of a shell, a rod slidably mounted in saidshell, cutters pivotally secured to one end of said rod, a nut adjustably secured to the opposite end of said rod, a spring surrounding said rod and interposed between saidI nut and a shoulder on the shell, a guide slot in said shell, and a key secured in an aperture in said nut and engaging with said guide slot, whereby said rod may be permitted to reciprocate, but prevented from turning in said shell. l

4. In an underreamer, the combination of a shell, arod slidably mounted in said shell, a spring tending to retract said rod, cutters mounted on said rod, a guide slot formed in said shell, an adjusting nut movably secured to the upper end of said rod and adapted to regulate the compression of said spring, and a key passing through said nut and engaging the slot Iormed in the shell, whereby the nut as well as the rod will be locked against a turning movement.

5. In an underreamer, the combination of a shell, a spring pressed rod slidably mounted in said shell, the lower end of said rod being provided with a cross bar the upper edges of which are formed into segmental bearing surfaces, said bar being provided with perforations, cutters mounted on said cross bar and held in position by means of keeper pins passing through said perforations, said pins being of smaller diameter than the perforations in the cross bar, and segmental shoulders provided on the cuttersl adapted to engage the segmental bearing shoulders of the cross bar, whereby when the cutters are in an operative position all strain on the keeper pins will be avoided.

In witness that I claim the foregoing I have hereunto subscribed my name this 16th day of July, 1918.

wILsoN B. wieLE. 

